Documents disponibles écrits par cet auteur

Constructal allocation of nanoparticles in nanofluids / Chao Bai in Journal of heat transfer, Vol. 132 N° 5 (Mai 2010) 

Public ISBD [article]  in Journal of heat transfer > Vol. 132 N° 5 (Mai 2010) . - pp. [052404-1/6] Titre : Constructal allocation of nanoparticles in nanofluids Type de document : texte imprimé Auteurs : Chao Bai, Auteur ; Liqiu Wang, Auteur Article en page(s) : pp. [052404-1/6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Blade  configuration  Design  Constructal  theory  Transition  line  Dispersed  configuration  Heat  sinks  Nanofluids  Nanoparticles Index. décimale : 536 Chaleur. Thermodynamique Résumé : We perform a constructal design of heat conduction in a blade-configured disk-shaped domain with uniform heat generation and periphery heat-sink by introducing a transition line from two-path conduction to one-path conduction in the domain. This orderly arranged blade configuration can offer significantly smaller constructal overall temperature difference than that of the dispersed configuration and thus performs much better. The constructal allocation of nanoparticles inside the base fluids and thus the heat-conduction design inside the nanofluids are very important for better system performance. This work shows that the search for heat-flow configuration is a key to performance, and the constructal theory is the strategy for discovering the configuration and the significantly better performance. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...] [article] Constructal allocation of nanoparticles in nanofluids [texte imprimé] / Chao Bai, Auteur ; Liqiu Wang, Auteur . - pp. [052404-1/6]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 132 N° 5 (Mai 2010) . - pp. [052404-1/6] Mots-clés : Blade  configuration  Design  Constructal  theory  Transition  line  Dispersed  configuration  Heat  sinks  Nanofluids  Nanoparticles Index. décimale : 536 Chaleur. Thermodynamique Résumé : We perform a constructal design of heat conduction in a blade-configured disk-shaped domain with uniform heat generation and periphery heat-sink by introducing a transition line from two-path conduction to one-path conduction in the domain. This orderly arranged blade configuration can offer significantly smaller constructal overall temperature difference than that of the dispersed configuration and thus performs much better. The constructal allocation of nanoparticles inside the base fluids and thus the heat-conduction design inside the nanofluids are very important for better system performance. This work shows that the search for heat-flow configuration is a key to performance, and the constructal theory is the strategy for discovering the configuration and the significantly better performance. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...]

Modeling bioheat transport at macroscale / Liqiu Wang in Journal of heat transfer, Vol. 133 N° 1(N° Spécial) (Janvier 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 1(N° Spécial) (Janvier 2011) . - pp. [011010/1-10] Titre : Modeling bioheat transport at macroscale Type de document : texte imprimé Auteurs : Liqiu Wang, Auteur ; Jing Fan, Auteur Année de publication : 2011 Article en page(s) : pp. [011010/1-10] Note générale : Physique Langues : Anglais (eng) Mots-clés : Bioheat  transport  Mixture  theory  Porous-medis  theory  Dual-phase-lagging  Blood-tissue  interaction  Macroscale  Modeling Index. décimale : 536 Chaleur. Thermodynamique Résumé : Macroscale thermal models have been developed for biological tissues either by the mixture theory of continuum mechanics or by the porous-media theory. The former uses scaling-down from the global scale; the latter applies scaling-up from the microscale by the volume averaging. The used constitutive relations for heat flux density vector include the Fourier law, the Cattaneo–Vernotte (Cattaneo, C., 1958, “A Form of Heat Conduction Equation Which Eliminates the Paradox of Instantaneous Propagation,” Compt. Rend., 247, pp. 431–433; Vernotte, P., 1958, “Les Paradoxes de la Théorie Continue de I'equation de la Chaleur,” Compt. Rend., 246, pp. 3154–3155) theory, and the dual-phase-lagging theory. The developed models contain, for example, the Pennes (1948, “Analysis of Tissue and Arterial Blood Temperature in the Resting Human Forearm,” J. Appl. Physiol., 1, pp. 93–122), Wulff (1974, “The Energy Conservation Equation for Living Tissues,” IEEE Trans. Biomed. Eng., BME-21, pp. 494–495), Klinger (1974, “Heat Transfer in Perfused Tissue I: General Theory,” Bull. Math. Biol., 36, pp. 403–415), and Chen and Holmes (1980, “Microvascular Contributions in Tissue Heat Transfer,” Ann. N.Y. Acad. Sci., 335, pp. 137–150), thermal wave bioheat, dual-phase-lagging (DPL) bioheat, two-energy-equations, blood DPL bioheat, and tissue DPL bioheat models. We analyze the methodologies involved in these two approaches, the used constitutive theories for heat flux density vector and the developed models. The analysis shows the simplicity of the mixture theory approach and the powerful capacity of the porous-media approach for effectively developing accurate macroscale thermal models for biological tissues. Future research is in great demand to materialize the promising potential of the porous-media approach by developing a rigorous closure theory. The heterogeneous and nonisotropic nature of biological tissue yields normally a strong noninstantaneous response between heat flux and temperature gradient in nonequilibrium heat transport. Both blood and tissue macroscale temperatures satisfy the DPL-type energy equations with the same values of the phase lags of heat flux and temperature gradient that can be computed in terms of blood and tissue properties, blood-tissue interfacial convective heat transfer coefficient, and blood perfusion rate. The blood-tissue interaction leads to very sophisticated effect of the interfacial convective heat transfer, the blood velocity, the perfusion, and the metabolic reaction on blood and tissue macroscale temperature fields such as the spreading of tissue metabolic heating effect into the blood DPL bioheat equation and the appearance of the convection term in the tissue DPL bioheat equation due to the blood velocity. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Modeling bioheat transport at macroscale [texte imprimé] / Liqiu Wang, Auteur ; Jing Fan, Auteur . - 2011 . - pp. [011010/1-10]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 1(N° Spécial) (Janvier 2011) . - pp. [011010/1-10] Mots-clés : Bioheat  transport  Mixture  theory  Porous-medis  theory  Dual-phase-lagging  Blood-tissue  interaction  Macroscale  Modeling Index. décimale : 536 Chaleur. Thermodynamique Résumé : Macroscale thermal models have been developed for biological tissues either by the mixture theory of continuum mechanics or by the porous-media theory. The former uses scaling-down from the global scale; the latter applies scaling-up from the microscale by the volume averaging. The used constitutive relations for heat flux density vector include the Fourier law, the Cattaneo–Vernotte (Cattaneo, C., 1958, “A Form of Heat Conduction Equation Which Eliminates the Paradox of Instantaneous Propagation,” Compt. Rend., 247, pp. 431–433; Vernotte, P., 1958, “Les Paradoxes de la Théorie Continue de I'equation de la Chaleur,” Compt. Rend., 246, pp. 3154–3155) theory, and the dual-phase-lagging theory. The developed models contain, for example, the Pennes (1948, “Analysis of Tissue and Arterial Blood Temperature in the Resting Human Forearm,” J. Appl. Physiol., 1, pp. 93–122), Wulff (1974, “The Energy Conservation Equation for Living Tissues,” IEEE Trans. Biomed. Eng., BME-21, pp. 494–495), Klinger (1974, “Heat Transfer in Perfused Tissue I: General Theory,” Bull. Math. Biol., 36, pp. 403–415), and Chen and Holmes (1980, “Microvascular Contributions in Tissue Heat Transfer,” Ann. N.Y. Acad. Sci., 335, pp. 137–150), thermal wave bioheat, dual-phase-lagging (DPL) bioheat, two-energy-equations, blood DPL bioheat, and tissue DPL bioheat models. We analyze the methodologies involved in these two approaches, the used constitutive theories for heat flux density vector and the developed models. The analysis shows the simplicity of the mixture theory approach and the powerful capacity of the porous-media approach for effectively developing accurate macroscale thermal models for biological tissues. Future research is in great demand to materialize the promising potential of the porous-media approach by developing a rigorous closure theory. The heterogeneous and nonisotropic nature of biological tissue yields normally a strong noninstantaneous response between heat flux and temperature gradient in nonequilibrium heat transport. Both blood and tissue macroscale temperatures satisfy the DPL-type energy equations with the same values of the phase lags of heat flux and temperature gradient that can be computed in terms of blood and tissue properties, blood-tissue interfacial convective heat transfer coefficient, and blood perfusion rate. The blood-tissue interaction leads to very sophisticated effect of the interfacial convective heat transfer, the blood velocity, the perfusion, and the metabolic reaction on blood and tissue macroscale temperature fields such as the spreading of tissue metabolic heating effect into the blood DPL bioheat equation and the appearance of the convection term in the tissue DPL bioheat equation due to the blood velocity. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]

Review of heat conduction in nanofluids / Jing Fan in Journal of heat transfer, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 4 (Avril 2011) . - pp. [040801/1-14] Titre : Review of heat conduction in nanofluids Type de document : texte imprimé Auteurs : Jing Fan, Auteur ; Liqiu Wang, Auteur Année de publication : 2011 Article en page(s) : pp. [040801/1-14] Note générale : Physique Langues : Anglais (eng) Mots-clés : Nanofluids  Heat  conduction  Experiments  Models  Dual-lagging  Thermal  wave Index. décimale : 536 Chaleur. Thermodynamique Résumé : Nanofluids—fluid suspensions of nanometer-sized particles—are a very important area of emerging technology and are playing an increasingly important role in the continuing advances of nanotechnology and biotechnology worldwide. They have enormously exciting potential applications and may revolutionize the field of heat transfer. This review is on the advances in our understanding of heat-conduction process in nanofluids. The emphasis centers on the thermal conductivity of nanofluids: its experimental data, proposed mechanisms responsible for its enhancement, and its predicting models. A relatively intensified effort has been made on determining thermal conductivity of nanofluids from experiments. While the detailed microstructure-conductivity relationship is still unknown, the data from these experiments have enabled some trends to be identified. Suggested microscopic reasons for the experimental finding of significant conductivity enhancement include the nanoparticle Brownian motion, the Brownian-motion-induced convection, the liquid layering at the liquid-particle interface, and the nanoparticle cluster/aggregate. Although there is a lack of agreement regarding the role of the first three effects, the last effect is generally accepted to be responsible for the reported conductivity enhancement. The available models of predicting conductivity of nanofluids all involve some empirical parameters that negate their predicting ability and application. The recently developed first-principles theory of thermal waves offers not only a macroscopic reason for experimental observations but also a model governing the microstructure-conductivity relationship without involving any empirical parameter. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...] [article] Review of heat conduction in nanofluids [texte imprimé] / Jing Fan, Auteur ; Liqiu Wang, Auteur . - 2011 . - pp. [040801/1-14]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 4 (Avril 2011) . - pp. [040801/1-14] Mots-clés : Nanofluids  Heat  conduction  Experiments  Models  Dual-lagging  Thermal  wave Index. décimale : 536 Chaleur. Thermodynamique Résumé : Nanofluids—fluid suspensions of nanometer-sized particles—are a very important area of emerging technology and are playing an increasingly important role in the continuing advances of nanotechnology and biotechnology worldwide. They have enormously exciting potential applications and may revolutionize the field of heat transfer. This review is on the advances in our understanding of heat-conduction process in nanofluids. The emphasis centers on the thermal conductivity of nanofluids: its experimental data, proposed mechanisms responsible for its enhancement, and its predicting models. A relatively intensified effort has been made on determining thermal conductivity of nanofluids from experiments. While the detailed microstructure-conductivity relationship is still unknown, the data from these experiments have enabled some trends to be identified. Suggested microscopic reasons for the experimental finding of significant conductivity enhancement include the nanoparticle Brownian motion, the Brownian-motion-induced convection, the liquid layering at the liquid-particle interface, and the nanoparticle cluster/aggregate. Although there is a lack of agreement regarding the role of the first three effects, the last effect is generally accepted to be responsible for the reported conductivity enhancement. The available models of predicting conductivity of nanofluids all involve some empirical parameters that negate their predicting ability and application. The recently developed first-principles theory of thermal waves offers not only a macroscopic reason for experimental observations but also a model governing the microstructure-conductivity relationship without involving any empirical parameter. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...]